The Small Animal Imaging Shared Resource (SAISR) was established as a JCCC Shared Resource in 2002, with a prototype microPET scanner, a microCT, a digital whole body autoradiograpy (DWBA) system and an optical imaging system. Twelve JCCC faculty formed the user base in 2002. During the past five years all initial SAISR instrumentation has been replaced; we currently have a dedicated imaging suite that houses a new microCT, two microPET instruments, a new cryostat and DWBA system, three bioluminescence/fluorescence optical imaging instruments and a Maestro spectral filtering fluorescence system. All instrumentation was obtained with institutional support. The SAISR has a dedicated vivarium for bngitudinal imaging studies. Our user base has grown to 44 faculty members who performed over 14,000 imaging experiments last year. JCCC members from seven Program Areas performed 86% of these studies. JCCC CCSG support for the SAISR is 14% of the SAISR operating budget. During 2008 the SAISR will move into a new 1500-sq. ft. imaging laboratory in the California NanoSystems Institute building. This facility will include a dedicated vivarium, procedure rooms, microPETs, microCT, bioluminescence, fluorescence and DWBA capabilities and adjacent space for a cyclotron dedicated to small animal imaging research and for radiochemistry facilities. This new physical facility is a tangible demonstration of institutional support for the SAISR in particular and the JCCC in general. The SAISR is full service, providing didactic classroom instruction and training in imaging instrumentation and animal handling protocols, individual instruction, online instruction, standard operating procedures for imaging procedures, on-line remote scheduling for instrumentation, data storage and archiving, data retrieval and data processing, on-site data retrieval for staff consultation and assistance in data processing, all probes and contrast reagents for microPET, microCT and optical imaging experiments, anesthetics, miscellaneous supplies (syringes, heating platforms, surgical materials, isolators for immunocompromised mice, multimodality imaging chambers designed by SAISR staff) and software for data analysis. Assistance is also provided for animal protocol preparation, radiation safety approval, data analysis and presentation and co-registration of multimodality images. All instruments are maintained and calibrated by SAISR staff. Critical staff, who have a long association with the JCCC, the SAISR and the investigators, provide both technical assistance and experimental guidance and expertise. In addition to assisting investigators with specific experimental protocols, the SAISR provides support to the investigators in the development and translation of new instrumentation, probes and contrast agents, and assists with biodistribution, dosimetry and toxicology studies. (Please also see Section 6.2.3 on Shared Resources in the History, Description, Essential Characteristics). 29 Cancer Center members representing eight Cancer Center Program Areas utilized the services of the Small Animal Imaging Shared Resource during the reporting period. This is a continuing shared resource.